Helicopter



W. A. CLARK July 28, 1931.

HELICOPTER Filed Oct. 5, 1927 2 Sheets-Shoot 1 INVENTOR.

' ATTORNEYS.

July 28, 1931; w. A. CLARK 1,316,315

- HELICOPTER Filed Oct. s, 1927 2 Sheets-Sheet 2 AIIIIIIIIIIIIIIII INVENTOR.

' ATTORNEYS.

Patented July 28, 1931 wnmm ewcmnxwor CALIFORNIA micomnn xp n stiani mea octets: 5,-"1a27; seriarfms:224-,'1521i z w-andtit: is prolvided Withlifting and-propulsioil :means adapted toeinsurew thatit x will be morer-efle'otively lifted and that a: heavier weightmay'helifted-with the expenditurenof lesswetiergy than vis now required.- for' I a? 'like operation in ide-vieesnow known: Thepres ehtdnvention contemplates-the provisiontofa frame struetlire carrying a") power pleantand mounted 'up on a running gear the. lrpper portilonof saidiframe structure being fitted with propulsionv propeiiers and liftingpropeliers, i thefllatter being so housedas tominimizeH-the wind resistance and-vto increaise therlitting powertofthepropellers; g The 'fnwentionwis i1lu2strated: Way; of ex- -amp1e in the.v

Whieh-.-, t

is .coneer ned..

thehel-ioopter. I I

Eigzz? is-a-view inepltanishowingrthe rangement of :the liiting propellersand the streamline :enclosnre.:thereforp I k:

, 'FigAsis an enlargued view iniplan showing thedetails of-the,liftingnpropellerst Eight); is an enlarged=viewintcentral vertical section seen on the line 5,-5 of Referring ore particularly tothe drawings, '10 indicates a rectangular platform structure fitted with. a running gear zomprising front and rear axles 1'1 and 12 and Wheels 13. Four Wheels are here shown as heing provided so that the structilremay be sup ported in' an upright position. Mounted "on the platform is a powerpla-n-t, h'e're shown as inoludhg an i ternai combustion engine 14', which "engineisfprovided witlf a driving These: pulleys are amdlarekadapted'tm clutch disks :18 and 19siidably moumtedupon azverticalshaft 20 disposed; attrightranglesfco "then re-11 the ccompanying. drawings, n v in elevation/showing the device :with which the present A invention a Fig. 2 is: a view inend elevation showing 7 in g shaft '20 through gears 41 mid 42 mounted through the lifting propellers as spaced emzhiother I altecnatekyvcontaet with the driving'shaft'llfi Ail'everfll is provided and operates .-.fonks *22 andfi23i'which engage collmrs up'omthe. olutchiidiskxand simultaneously shifts ooilarsi'amdttheiflisks associated therewith.

A superstructure its-disposed above-Abe: platformllo and oompriseszuprights 1% canying an: overhead rectangular frame structure 25. This' frame structure consists;- of: horizontal frame 'memhersfifii and/27 E anfitventimal connecting members" 28: The reotmugufsar:

frame structure: supports lifti'ng': pmpei- I lers 29- azmd 30 'andi their cflindfrieal housings '31 and The re'c tangmlar frame strmture extends beyond theh ousings 331iantb32 'at'its opposite ends *and' oarriesa frame "structure" 33 which comesatowpoint in front ofitheqmopeller housing 32 and extends m mar and outwardly tU'the sifleSfof the memberzfitland sides as indieated 31,1345; to

thereafter be broughta'round the cylindl'i ical housingfil and broughtito a point of comersion irr tlre rear of saidhousi-ng wherebym stream linee'tfieot 11 'be-prodweeditoilessen the wind resistance which wou lda otli'eewi'se be oflered f by --the' cylindrical housing mamb'ers 31 and'32i The prope11ers 29 and 3qare fitted with verti'oal driveshaft's 35 which" shaftsex tend downwardly through suitablebearings: and carry gears 37= and 38 respectively. 7 These-gears' mesh with" driv gears 39 and 4:0 and i are driven by th uponthe shaft' 20 and azsh'aft 43'respectiwelv Due to the" arrangement "as shown 1 in Fig." (1,

it will be evident-= that thezlifti-ng" propellers 29' and 30' wil l hefconstantly drivenin oppo- Aiepropeller-strumre 424 is disposed atthe to the blades on propeller 30.

forward end of the helicopter for the purpose of propelling the aircraft horizontally. This propeller is provided with a universal drive connection 45 which connects it with a horizontal drive shaft 46. The horizontal shaft is fitted with pulleys 47 and 48 upon which a belt 49 may be selectively disposed by a shifting rod 50. The pulley 47 is idle upon the shaft 46 while the pulle 48 is keyed thereto. It will thus be evident that when it is desired not to drive the horizontal propulsion propeller, the shifting of the belt 49 from the keyed shaft 48 to the shaft 47 will cause the propeller 44 to remain idle. An operating lever 51 is keyed to the shifting rod to facilitate in shifting the belt. The belt 49 passes around a suitable pulley 52 carried on the forward end of shaft 15 of engine 14. The propeller 44 may be disposed in various positions in angular relation to its driving shaft 46 by manipulation of a spider 53. This spider has four arms disposed at right angles to each other and in the same plane, and the spider is mounted for universal movement upon a bearing 54.

Each of the arms is fitted with a cable 55 secured to the outer ends of arms 56 of a spider disposed adjacent the propeller 44 and carried upon a short propeller shaft 57 through which the propeller is driven from the universal. joint 45. It is to be understood that the frame structure comprising the platform 10 and the upper frame 25 may be suitably provided with transverse bracing to give it rigidity and to insure that it will resist wind stresses. This bracing may be in the form of cables 58.

One of the principal features of improvement of the present device is the lifting propeller construction and it is to be understood that, while the propellers 29 and 30 are here shown as disposed upon vertical axes for the lifting of the vehicle, it may be desirable to susbtitute a propeller of similar design for the propeller 44 without departing from the spirit of the present invention. The pro pellers 29 and. 30 are identical with the excep- 'tion that'their blades are pitched in opposite directions and that the two propellers move in opposite directions, as indicated by the arrows A and B in Fig. 3.

The blades of the lifting propellers are also clearly shown in Fig. 4, where it will. be seen that the blades on propeller 29 are disposed at This has been proven to be of advantage in causing the two lifting propellers to balance each other and more satisfactorily cooperate in manipulation of the aircraft. The wings are warped around the shaft for a distance slightly greater than 90 so that the upper and lower contiguous edges of adjacent blades will. overlap as shown in Figs. 4 and. 5. The marginal edge of each of the blades deflects downwardly to form a bankingwing 63 against which the air set in motion by the main warped portion of the blade will be thrown by centrifugal force and will be then deflected downwardly, the force of which action will increase the lifting efliciency of the blade. In fact, experience has proven that by pro viding a propeller having straight warped blades 62 and a propeller having the blades with the outer deflecting margins 63, the last named structures will lift approximately seven times the weight lifted by the straight warped blades when the two are driven at the same rate of speed and are of substantially the same over-all dimensions. The blades 62 thus formed are braced by guy wires 64 which are secured to the shafts therefor at points above and below the propeller structures.

In the operation of the present invention, the engine 14 is started and its shaft 15 is driven. It will be assumed that the shaft is rotating in a clockwise direction as viewed from the rear and that the friction wheels 16 and 17 will tend to rotate the disk 18 to cause the lifting propellers 29 and 30 to rotate in the direction of the arrows A and B as indicated in Fig. 3 of the drawings. This action will lift the aircraft and as the lifting propellers rotate. their blades will pass through the air to displace the air and will. at the same time force the air out by centrifugal action against the deflecting margins 63 of the blade. therebv causing increased lifting action as the air is displaced and the aircraft is lifted. VVhen the aircraft has reached a desired elevation. the lever 59 mav be operated to shift the belt 49 from the idler 47 to the pulley 48. This will establish a drivinc connection from the en wine to the propeller shaft 4-6 and will drive the propulsion pro eller 44. It will. of course. be understood that in the event ascension is to, be made in an ohioue direction to the round. the pro eller 44 mav be driven before the elevation is reached and. in fact. bv manipulation of the spider 53. the propeller ma be dis osed at an angle to the horizontal so that it wi l assist in elevating the aircraft as it travels alone" its oblique course. .Tf it is desired to reverse the direction of rotation of the liftipo propellers 29 and 30. the lever 21 .rnav be o erated to swing the disk 19 into ensra gement with the friction wheels 16 and 17 and to simultaneously move the d sk 18 out of enga ement therewith. thus reversing the direction of rotation of the shaft 20.

It will thus be seen that the structure here disclosed provides improved means for the operation. of a heavier-than-air craft and 1 that by the propeller construction here disclosed, improved lifting conditions may be brought about. It is also to be understood that while the propellers are shown as being used for lifting propellers it may be desirable to use them for propulsion propellers, either in airor liquids.

I Want to call particular attention to the fact that the blades of the lifting propellers extend radially about the propeller shaft and lie in substantially the same plane with their radial axis at rightangles to the axis about which the propeller revolves.

I also desire to point out that these convolute blades of the lifting propellers are bent at their outer ends so that their tips. will lie at an angle to the axis of the blades so as to intercept the centrifugal'blast of air created by the propellers when in operation.

5 In this manner I utilize this centrifugal force to aid the propeller in lifting or pulling.

It is thus obvious that my propeller will be a great deal more eflicient than those now in use because these latter entirely lose the effectiveness of the air escaping in a radial direction.

While I have shown the preferred form of my invention, it is to be understood that various changes may be made in its construction by those skilled in theart without departing from the spirit of the invention, as defined in the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A lifting propeller for a helicopter comprising four blades extending radially about the axis of the propeller and with their contiguous edges overlapping, the radial axis 3 of said blades extending at right angles to the axis of the propeller, and the outer portions of said blades being inturned at an obtuse angle to the axis of the blades to intercept the centrifugal fluid blast created when the propeller isin operation.

2. A lifting propeller for helicopters comprising a plurality of blades extending radially about the axis of the propeller, the radial axis of said blades extending at right.

angles to the axis of the propeller, the outer portions of said blades being inturned at an obtuse angle to the axis of the blades andarcuate concentric to the axis of the propeller whereby said outer portions of the blades will intercept the centrifugal fluid blast and utilize the same in a lifting action.

3. A lifting propeller for helicopters comprising a plurality of helical blades extending radially about the axis of a propeller in circumferential alignment, the radial axis of said blades extending at right angles to the axis of the propeller, the outer portions of said blades being inturned at an obtuse angle to the radial axis of the blades and arcuate concentric to the axis of the propeller whereby said outer portions of the blades will intercept the centrifugal fluid blast and utilize the same in a lifting action.

WILLIAMIX. CLARK. 

